xref: /freebsd/contrib/tcp_wrappers/scaffold.c (revision 40a8ac8f62b535d30349faf28cf47106b7041b83)
1  /*
2   * Routines for testing only. Not really industrial strength.
3   *
4   * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
5   *
6   * $FreeBSD$
7   */
8 
9 #ifndef lint
10 static char sccs_id[] = "@(#) scaffold.c 1.6 97/03/21 19:27:24";
11 #endif
12 
13 /* System libraries. */
14 
15 #include <sys/types.h>
16 #include <sys/stat.h>
17 #include <sys/socket.h>
18 #include <netinet/in.h>
19 #include <arpa/inet.h>
20 #include <netdb.h>
21 #include <stdio.h>
22 #include <syslog.h>
23 #include <setjmp.h>
24 #include <string.h>
25 
26 #ifndef INADDR_NONE
27 #define	INADDR_NONE	(-1)		/* XXX should be 0xffffffff */
28 #endif
29 
30 #ifndef INET6
31 extern char *malloc();
32 #endif
33 
34 /* Application-specific. */
35 
36 #include "tcpd.h"
37 #include "scaffold.h"
38 
39  /*
40   * These are referenced by the options module and by rfc931.c.
41   */
42 int     allow_severity = SEVERITY;
43 int     deny_severity = LOG_WARNING;
44 int     rfc931_timeout = RFC931_TIMEOUT;
45 
46 #ifndef INET6
47 /* dup_hostent - create hostent in one memory block */
48 
49 static struct hostent *dup_hostent(hp)
50 struct hostent *hp;
51 {
52     struct hostent_block {
53 	struct hostent host;
54 	char   *addr_list[1];
55     };
56     struct hostent_block *hb;
57     int     count;
58     char   *data;
59     char   *addr;
60 
61     for (count = 0; hp->h_addr_list[count] != 0; count++)
62 	 /* void */ ;
63 
64     if ((hb = (struct hostent_block *) malloc(sizeof(struct hostent_block)
65 			 + (hp->h_length + sizeof(char *)) * count)) == 0) {
66 	fprintf(stderr, "Sorry, out of memory\n");
67 	exit(1);
68     }
69     memset((char *) &hb->host, 0, sizeof(hb->host));
70     hb->host.h_length = hp->h_length;
71     hb->host.h_addr_list = hb->addr_list;
72     hb->host.h_addr_list[count] = 0;
73     data = (char *) (hb->host.h_addr_list + count + 1);
74 
75     for (count = 0; (addr = hp->h_addr_list[count]) != 0; count++) {
76 	hb->host.h_addr_list[count] = data + hp->h_length * count;
77 	memcpy(hb->host.h_addr_list[count], addr, hp->h_length);
78     }
79     return (&hb->host);
80 }
81 #endif
82 
83 /* find_inet_addr - find all addresses for this host, result to free() */
84 
85 #ifdef INET6
86 struct addrinfo *find_inet_addr(host)
87 char   *host;
88 {
89     struct addrinfo hints, *res;
90 
91     memset(&hints, 0, sizeof(hints));
92     hints.ai_family = PF_UNSPEC;
93     hints.ai_socktype = SOCK_STREAM;
94     hints.ai_flags = AI_PASSIVE | AI_NUMERICHOST;
95     if (getaddrinfo(host, NULL, &hints, &res) == 0)
96 	return (res);
97 
98     memset(&hints, 0, sizeof(hints));
99     hints.ai_family = PF_UNSPEC;
100     hints.ai_socktype = SOCK_STREAM;
101     hints.ai_flags = AI_PASSIVE | AI_CANONNAME;
102     if (getaddrinfo(host, NULL, &hints, &res) != 0) {
103 	tcpd_warn("%s: host not found", host);
104 	return (0);
105     }
106     if (res->ai_family != AF_INET6 && res->ai_family != AF_INET) {
107 	tcpd_warn("%d: not an internet host", res->ai_family);
108 	freeaddrinfo(res);
109 	return (0);
110     }
111     if (!res->ai_canonname) {
112 	tcpd_warn("%s: hostname alias", host);
113 	tcpd_warn("(cannot obtain official name)", res->ai_canonname);
114     } else if (STR_NE(host, res->ai_canonname)) {
115 	tcpd_warn("%s: hostname alias", host);
116 	tcpd_warn("(official name: %.*s)", STRING_LENGTH, res->ai_canonname);
117     }
118     return (res);
119 }
120 #else
121 struct hostent *find_inet_addr(host)
122 char   *host;
123 {
124     struct in_addr addr;
125     struct hostent *hp;
126     static struct hostent h;
127     static char *addr_list[2];
128 
129     /*
130      * Host address: translate it to internal form.
131      */
132     if ((addr.s_addr = dot_quad_addr(host)) != INADDR_NONE) {
133 	h.h_addr_list = addr_list;
134 	h.h_addr_list[0] = (char *) &addr;
135 	h.h_length = sizeof(addr);
136 	return (dup_hostent(&h));
137     }
138 
139     /*
140      * Map host name to a series of addresses. Watch out for non-internet
141      * forms or aliases. The NOT_INADDR() is here in case gethostbyname() has
142      * been "enhanced" to accept numeric addresses. Make a copy of the
143      * address list so that later gethostbyXXX() calls will not clobber it.
144      */
145     if (NOT_INADDR(host) == 0) {
146 	tcpd_warn("%s: not an internet address", host);
147 	return (0);
148     }
149     if ((hp = gethostbyname(host)) == 0) {
150 	tcpd_warn("%s: host not found", host);
151 	return (0);
152     }
153     if (hp->h_addrtype != AF_INET) {
154 	tcpd_warn("%d: not an internet host", hp->h_addrtype);
155 	return (0);
156     }
157     if (STR_NE(host, hp->h_name)) {
158 	tcpd_warn("%s: hostname alias", host);
159 	tcpd_warn("(official name: %.*s)", STRING_LENGTH, hp->h_name);
160     }
161     return (dup_hostent(hp));
162 }
163 #endif
164 
165 /* check_dns - give each address thorough workout, return address count */
166 
167 int     check_dns(host)
168 char   *host;
169 {
170     struct request_info request;
171 #ifdef INET6
172     struct sockaddr_storage sin;
173     struct addrinfo *hp, *res;
174 #else
175     struct sockaddr_in sin;
176     struct hostent *hp;
177 #endif
178     int     count;
179     char   *addr;
180 
181     if ((hp = find_inet_addr(host)) == 0)
182 	return (0);
183     request_init(&request, RQ_CLIENT_SIN, &sin, 0);
184     sock_methods(&request);
185 #ifndef INET6
186     memset((char *) &sin, 0, sizeof(sin));
187     sin.sin_family = AF_INET;
188 #endif
189 
190 #ifdef INET6
191     for (res = hp, count = 0; res; res = res->ai_next, count++) {
192 	memcpy(&sin, res->ai_addr, res->ai_addrlen);
193 #else
194     for (count = 0; (addr = hp->h_addr_list[count]) != 0; count++) {
195 	memcpy((char *) &sin.sin_addr, addr, sizeof(sin.sin_addr));
196 #endif
197 
198 	/*
199 	 * Force host name and address conversions. Use the request structure
200 	 * as a cache. Detect hostname lookup problems. Any name/name or
201 	 * name/address conflicts will be reported while eval_hostname() does
202 	 * its job.
203 	 */
204 	request_set(&request, RQ_CLIENT_ADDR, "", RQ_CLIENT_NAME, "", 0);
205 	if (STR_EQ(eval_hostname(request.client), unknown))
206 	    tcpd_warn("host address %s->name lookup failed",
207 		      eval_hostaddr(request.client));
208     }
209 #ifdef INET6
210     freeaddrinfo(hp);
211 #else
212     free((char *) hp);
213 #endif
214     return (count);
215 }
216 
217 /* dummy function to intercept the real shell_cmd() */
218 
219 /* ARGSUSED */
220 
221 void    shell_cmd(command)
222 char   *command;
223 {
224     if (hosts_access_verbose)
225 	printf("command: %s", command);
226 }
227 
228 /* dummy function  to intercept the real clean_exit() */
229 
230 /* ARGSUSED */
231 
232 void    clean_exit(request)
233 struct request_info *request;
234 {
235     exit(0);
236 }
237 
238 /* dummy function  to intercept the real rfc931() */
239 
240 /* ARGSUSED */
241 
242 void    rfc931(request)
243 struct request_info *request;
244 {
245     strcpy(request->user, unknown);
246 }
247 
248 /* check_path - examine accessibility */
249 
250 int     check_path(path, st)
251 char   *path;
252 struct stat *st;
253 {
254     struct stat stbuf;
255     char    buf[BUFSIZ];
256 
257     if (stat(path, st) < 0)
258 	return (-1);
259 #ifdef notdef
260     if (st->st_uid != 0)
261 	tcpd_warn("%s: not owned by root", path);
262     if (st->st_mode & 020)
263 	tcpd_warn("%s: group writable", path);
264 #endif
265     if (st->st_mode & 002)
266 	tcpd_warn("%s: world writable", path);
267     if (path[0] == '/' && path[1] != 0) {
268 	strrchr(strcpy(buf, path), '/')[0] = 0;
269 	(void) check_path(buf[0] ? buf : "/", &stbuf);
270     }
271     return (0);
272 }
273